Calibration of electrical parameters in optically switchable windows

Abstract

The embodiments herein relate to methods for controlling an optical transition and the ending tint state of an optically switchable device, and optically switchable devices configured to perform such methods. In various embodiments, non-optical (e.g., electrical) feedback is used to help control an optical transition. The feedback may be used for a number of different purposes. In many implementations, the feedback is used to control an ongoing optical transition. In some embodiments a transfer function is used calibrate optical drive parameters to control the tinting state of optically switching devices.

What is claimed is: 
     
       1. A method of controlling tint level for a plurality of electrochromic devices, the method comprising:
 receiving a command to change tint level of the plurality of electrochromic devices; 
 consulting transfer functions for tint level relative to a drive parameter for each of the plurality of electrochromic devices, wherein at least one of the plurality of electrochromic devices has a transfer function differing from at least one other of the plurality of electrochromic devices; and 
 driving each of the plurality of electrochromic devices in accordance with the transfer functions, so as to substantially match the tint levels or tint rates across the plurality of electrochromic devices. 
 
     
     
       2. The method of  claim 1 , further comprising:
 determining current-controlled parameters to apply to each of the plurality of electrochromic devices, based on a tint level in accordance with the command and based on the transfer functions. 
 
     
     
       3. The method of  claim 2 , wherein the current-controlled parameters are initial current ramp rates. 
     
     
       4. The method of  claim 1 , further comprising:
 determining voltage-controlled parameters to apply to each of the plurality of electrochromic devices, based on a tint level in accordance with the command and based on the transfer functions. 
 
     
     
       5. The method of  claim 4 , wherein the voltage-controlled parameters are drive voltages. 
     
     
       6. The method of  claim 4 , wherein the voltage-controlled parameters are voltage ramp rates. 
     
     
       7. The method of  claim 4 , wherein the voltage-controlled parameters are ramp to hold voltages. 
     
     
       8. The method of  claim 4 , wherein the voltage-controlled parameters are hold voltages. 
     
     
       9. The method of  claim 8 , wherein the transfer functions are stored in a storage device that is located remote from the plurality of electrochromic windows. 
     
     
       10. The method of  claim 1 , further comprising:
 obtaining the transfer functions via a network. 
 
     
     
       11. The method of  claim 10 , wherein the storage device is located within a master controller on the network. 
     
     
       12. The method of  claim 10 , wherein the storage device is located within an administrative control system. 
     
     
       13. The controller of  claim 12 , wherein the one or more processors are configured to obtain the first transfer function and the second transfer function over a network. 
     
     
       14. The controller of  claim 12 , wherein the first transfer function and the second transfer function are stored in a storage device that is located remotely from the from the first electrochromic window and from the second electrochromic window. 
     
     
       15. The controller of  claim 12 , wherein the first transfer function and the second transfer function are stored in the memory component of the controller. 
     
     
       16. The controller of  claim 12 , wherein the first transfer function and the second transfer function are stored in a storage device located within an administrative control system. 
     
     
       17. The controller of  claim 12 , wherein the one or more processors are configured to determine the first transfer function and the second transfer function based on user feedback. 
     
     
       18. A controller for matching tint levels across a first electrochromic device and a second electrochromic device, the controller comprising:
 one or more processors configured to communicate with at least the first electrochromic device and the second electrochromic device, and configured to perform a method comprising:
 consulting a first transfer function for the first electrochromic device and consulting a second transfer function for the second electrochromic device, the first transfer function and second transfer function each relating tint level to a drive parameter, and 
 driving the first electrochromic device in accordance with the first transfer function, and driving the second electrochromic device in accordance with the second transfer function to thereby match the tint levels or tint rates between the first electrochromic device and the second electrochromic device. 
 
 
     
     
       19. The controller of  claim 18 , further comprising a memory component storing the first transfer function and the second transfer function. 
     
     
       20. The controller of  claim 18 , wherein the one or more processors are configured to determine current-controlled parameters to apply to the first electrochromic device and to the second electrochromic device. 
     
     
       21. The controller of  claim 20 , wherein the current-controlled parameters are initial current ramp rates. 
     
     
       22. The controller of  claim 21 , wherein the voltage-controlled parameters are hold voltages. 
     
     
       23. The controller of  claim 18 , wherein the one or more processors are configured to determine voltage-controlled parameters to apply to the first electrochromic device and to the second electrochromic device. 
     
     
       24. The controller of  claim 23 , wherein the voltage-controlled parameters are drive voltages. 
     
     
       25. The controller of  claim 23 , wherein the voltage-controlled parameters are voltage ramp rates. 
     
     
       26. The controller of  claim 23 , wherein the voltage-controlled parameters are ramp to hold voltages.